1. Technical Field
The present invention relates to a method of managing IP addresses, and more particularly, to a method of managing IP addresses to improve convenience using a plurality of address acquisition methods under IPv6.
2. Related Art
In the related art, a network communication device such as a personal computer performing communication via the Internet has an IP address, which is an address on the Internet, and performs communication with other devices using that IP address. As a protocol of the communication, IPv4 (Internet Protocol Version 4) has been used, but there is the problem of a lack of IP addresses, and thus IPv6 (Internet Protocol Version 6) has been proposed.
Under IPv6, the address space is drastically expanded, one device can have a plurality of IP addresses, and a plurality of methods of acquiring IP addresses are provided.
In JP-A-11-196135, it is proposed that a large number of private IP addresses are associated with a small number of global IP addresses and are converted.
However, under IPv6 described above, when the same IP address is generated by different acquisition methods and duplicated, the address which can be obtained by any method of the acquisition methods is valid and can be used, and when the address obtained by the acquisition method disappears due to the valid lifetime or the like, the same IP address disappears. That is, the same address obtained by another acquisition method also disappears, even if the reason for disappearance does not occur in the address itself.
In this case, to continue using the IP address, a re-acquisition process is necessary again, this is not efficient, nor convenient.